Calcium Phosphate Nanocluster-Loaded Injectable Hydrogel for Bone Regeneration

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Nanotechnology

Background:

• Bone regeneration faces challenges in matching implant composition, biocompatibility, and mechanical properties.
• Biomineralization often involves hydrogel-like matrices and amorphous calcium phosphate (ACP) nanoclusters.

Purpose of the Study:

• To develop an injectable, bioinspired bone regeneration material using a hydrogel loaded with polymer-stabilized ACP nanoclusters.
• To evaluate the material's ability to promote hydroxyapatite (HAP) mineralization and bone healing.

Main Methods:

• Fabrication of a biocompatible hydrogel loaded with ∼1 nm polymer-stabilized ACP nanoclusters.
• Assessment of hydrogel's bone affinity, cellular response (proliferation and differentiation) ex vivo.
• Evaluation of bone defect filling, tissue integration, and mechanical properties in vivo using rat models.

Main Results:

• The cluster-loaded hydrogel facilitated intrafibrillar HAP mineralization within collagen fibrils.
• Ex vivo studies showed excellent bone affinity and supported bone cell activity.
• In vivo experiments demonstrated HAP-based defect fillings with native bone-like mechanical performance and seamless integration.

Conclusions:

• The cluster-loaded hydrogel is a promising injectable biomaterial for bone regeneration.
• This approach mimics natural biomineralization for effective bone defect repair.
• The material offers a minimally invasive, syringe-injectable solution for bone healing.